Apparatus for electroplating



May 9, H950 J. M. KENNEDY ET AL APPARATUS FOR ELECTROPLATING Filed Nov.23, 1945 6 Sheets-Sheet l 88. Maw 09% s.

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Jamealfllfenned bg'fi bug'Pfln are drIL May 9, 1950 J. M. KENNEDY ET ALI 5 9 APPARATUS FOR ELECTROPLATING Filed Nov. 23, 1945 6 Sheets-Sheet 2Inve'nifors JamesMmnmtg g; flrZhuz'PKmyhZ N HizroZdJLee.

6- Sheets-Sheet 3 9, 1950 J M KENNEDY ET AL APPARATUS FOR ELECTROPLATINGFiled Nov. 2", 1945 May 9, 3950 J. M. KENNEDY ET AL APPARATUS FORELECTROPLATING Filed Nov. 23, 1945 6 Sheets-Sheet 4 A NWQWN hi ZV M m nh$1M W .W I ma m 5 5 5 W M m y y 0 .1. M. KENNEDY ET AL 2,506,794

APPARATUS FOR ELECTROPLATING 6 Sheets-Sheet 5 acoo- A i v 4 I39 7 pan-we0e acac an- I nveni/ons: Jams MKezzne i d1 rihurPKn/igh May 9, 1950 J.M. KENNEDY ET AL APPARATUS FOR ELECTROPLATING Filed Nov. 23, 1945 6Sheets-Sheet 6 Q Irv/2192123021; Jamafllfenmdy oumnuuL Patented May 9,1950 UNITED STATES TENT OFFICE APFARATUS FOR ELECTBOPLATING ration ofMaryland Application November 23, 1945, Serial No. 630,266

4 Claims.

Our invention relates to methods of and apparatus for electroplating.

The invention has among its objects cladding the bottom portion of acooking vessel or the like with a coating of metal such as copper, withprovision for forming the coating with a marginal portion of graduallydecreasing thickness as the edge of the coating is approached. From thisaspect the invention constitutes an improvement in the method ofelectrodepositing the relatively thick copper coating according to thedisclosure of applicants Patent 2,363,973, issued November 28, 1944, andrelates to apparatus for the practice of such improvement.

The invention, however, will be best understood from the followingdescription when read in the light of the accompanying drawings ofseveral embodiments of apparatus according to the invention, the scopeof which latter will be more particularly pointed out in the appendedclaims.

In the drawings:

Fig. 1 is a transverse section of plating apparatus according to theinvention, corresponding to a section on the line l-l of Figs. 6, 7 and8;

Fig. 2 is a section on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary section, on an enlarged scale, on the line 33 ofFig. 6;

Fig. 4 is an elevation of a fragment of the chain for moving the articlecarriers;

Fig. 5 is a plan of the chain according to Fig. 4;

Fig. 6 is a plan of a fragment of the plating apparatus according toFig. 1;

Fig. 7 is a plan, on a reduced scale, of the plating apparatus accordingto Figs. 1 and 6, with parts broken away and parts omitted, including aschematic diagram of the control mechanism;

Fig. 8 is a longitudinal section of plating apparatus according to Figs.1, 6 and 7, with parts in elevation and parts broken away;

Figs. 9 and 10 are more or less diagrammatic views illustrating thearrangement of carrier supports according to Figs. 1 to 8;

Figs. l1, l2 and 13 are, respectively, sections on an enlarged scale onthe lines H-l l, l2- l2 i3l3 of Fig.7;

Fig. 14 is a side elevation of the apparatus according to Figs. 1 to 13,with parts omitted and parts broken away;

Fig. 15 is a section on the line l5i 5 of Fig. 14;

Fig. 16 is a fragmentary transverse section of a modified form ofapparatus, corresponding to Fig. 1, with parts omitted;

Fig. 17 is a fragmentary plan of the apparatus according to Fig. 16illustrating a detail;

Fig. 18 is a fragmentary side elevation of the apparatus according toFig. 16, with parts omitted, more or less diagrammatically illustratinga portion of the article carrier support;

Fig. 19 is a fragmentary transverse section of a further modified formof apparatus, corresponding to Fig. 1, with parts omitted;

Fig. 20 is a section on the line 2l32ll of Fig. 19;

Fig. 21 is a fragmentary side elevation of the apparatus according toFig. 19, with parts omitted and parts broken away, more or lessdiagrammatically illustrating a portion of the article carrier support;

Fig. 22 is a fragmentary section, on an enlarged scale, of the lowercorner portion of the vessel according to Fig. 2 showing anelectrodeposited plating or coating applied thereto; and

Fig. 23 is a modified form of vessel, according to Fig. 22, showing anelectrodeposited plating or coating applied thereto.

Referring particularly to the modification of the apparatus illustratedby Figs. 1 to 14, an elongated tank I, preferably formed of lead coatedsteel, is adapted to contain a body of electrolyte the upper surfacelevel of which is. indicated at L (Fig. 1). As shown, in thiselectrolyte are immersed the lower portions of cooking vessels or likearticles A, the bottom portions of which are to be clad with arelatively thick coating of metal such as copper.

The upper edges of the tank are shown as provided with longitudinallyextending horizontal flanges 3 upon which, at each of oppositelongitudinal sides of the tank, rests a strip 5 of insulating materialsuch as fiber. Supported on these strips are bus-bars 1 preferably ofcopper. For securing the bus-bars and insulating strips to the flangesare shown bolts 9 extending from the lower sides of the flanges throughthe strips -5 and tapped into the bus-bars l, the bolts being insulatedfrom the flanges by the insulating bushings II. Connected to the outeredges of the bus-bars l, as by brazing or welding, are cable lugs 13 towhich are connected the cables [5 and ii for connecting the bus-bars tothe opposite terminals, respectively, of the source of current supply.

As shown, connected to the inner edge of one of the bus-bars l, as bybrazing or welding, are the upper ends of the downwardly directedportions IQ of bars having horizontal portions 2| submerged in theelectrolyte, these horizontal portions extending transversely across thetank.

As shown, the bars i9, 2| are supported on suitable brackets 23 carriedby the side walls of the tank, which brackets are also preferably leadcovered to render them inert with respect to the electrolyte. Carried bythe horizontal portions 2! of each of the bars are shown a pinrality ofspaced anodes, herein two. These anodes, as illustrated, compriseannular trays 25, preferably formed of lead or other conductive materialinert with respect to the electrolyte, which trays are filled with amass 21 of copper shot or the like forming a readily replenishable orrenewable soluble anode.

The above mentioned trays 25 are shown as resting upon disks 29,preferably formed of copper and welded to the upper side of the barportions 2!. As shown, each disk is formed with an upwardly projectingnipple 3-! received in the opening of the annular tray 25. Asillustrated, the nipple and disk are formed with an opening 33 which iscontinued to the under side of the bar portion 2!. In the upper end ofthis opening is screw-threaded a nozzle 35 formed of hard rubber orother suitable insulating material, the edge of the nozzle overlying theedge of the annular tray 25 so that the nozzle secures it to the disk 25in electrical contact therewith.

As shown, each nozzle 35 is provided with a group of upwardly directedopenings 31 (Fig. 6) for projecting electrolyte upward toward the bottomof the vessel A, and with distributed radially directed openings 39(Figs. 1 and 6) for proiecting electrolyte in all directions radially ofthe bottom of the vessel. For supplying electrolyte under pressure tothe nozzle, screw-threaded into the lower ends of the opening 33 isshown a pipe connection 4|, preferably formed of lead, which isconnected by a length of rubber hose 43, or conduit of other insulatingmaterial, to the outlet nipples 65 of a lead pipe 4! extendinglongitudinally of the tank. As shown (Fig. 7) this pipe has a portion 39connected to the outlet of a motor driven pump 5| at the exterior of thetank, the inlet of the pump being connected to the tank by a pipe 53 soas to draw electrolyte therefrom and supply it to the pipe 49, in whichway the electrolyte is circulated.

Supported on posts 55 (Figs. 1 and 3) carried by the bar portions 2| arering members 51 having flanged radially extending portions 59, uponwhich latter rest annular metal shields 6i positioned between the anodesand the peripheral portions of the vessels. As shown, the exposedportions of the bar portions 2|, disks 29, posts 55, ring members 51 andshields Bl are covered with a layer 63, of rubber or other insulatingmaterial, for protecting and insulating them the electrolyte. As shown,the shield is removable so that shields with different size openings 6may be substituted to accommodate vessels of different diameters.

The above described nozzles 35 and shields G! are identical with thosedisclosed in the above mentioned patent, and are arranged dimensionallywith relation to each other and the anode and vessel as therein shownand described, and serve the same purpose. Briefly; this purpose is byuse of the nozzle to permit, in conjunction with the rotating vessel, ahigher current density per unit of cathode surface and eliminate thepossibility of quiescent spots in the electrolyte at the axial portionof the bottom of the rotating vessel, while the shield causes the pathof travel of the plating current from the anode to the vesselprogressively to increase from points opposite the inner peripheral edgeof the annular shield to the edges of the surface being plated, hence tocause the value of the current and consequent rate of depositionprogressively to diminish from points opposite the inner peripheral edgeof the shield to the edge of the surfaces being plated as compared towhat they would be were the shield omitted.

As shown, the vessels A are supported by carriers comprising the spacedbars 65 which are preferably formed of metal such as brass and areintegrally connected at their ends by cross-bars 61. As shown, at theintermediate portions of the carrier are cross-bars 69 integrally formedwith the bars 55. These bars 69 have depending portions 7! which areperforated for fixedly carrying elongated sleeves 13, in which latterare rotatably mounted vertical shafts 15. As shown, carried by the lowerend of each shaft 15 is a chuck for supporting the vessel A. The chuck,which is preferably formed of resilient sheet copper, has a bottom 71'to which the shaft 75 is joined, as by welding, and has side wallsformed with l -shaped splits 19 to form a circular series of spacedresilient prongs 8|, the latter engaging the lower portions of the sidewalls of the vessel for supporting it and detachably connecting it tothe shaft 15. As shown, each shaft 15 is provided at its upper end witha bevel gear 83 meshing with a bevel gear 85 on a horizontal shaft 81rotatably supported in bearings 89 on the carrier crossbars 69. Theshaft 81 is shown as connected by an insulating coupling 9! to anelectric motor 93 for driving said shaft, the motor being supported on aplate 95 of insulating magerial carried at opposite ends by the sidebars For energizing the motor 93 the plate 95 of insulating materialwhich supports it carries a pair of downwardly projecting brushes 97connected by leads 98 (Fig. l) to the motor terminals. These brusheshave contact portions 93 engaging the flat bar-like trolley wires H]!extending longitudinally of the tank. As shown. these trolley wires arecarried by brackets Hi3 supported by the adjacent side wall of the tank,insulating strips 95 being positioned between the wires and thebrackets, these bars and strips being conveniently secured to thebrackets in the same way as the bus-bars l and insulating strips 5 aresecured to the tank flanges 3. The brushes 9'! are of a known type inwhich the contact portions 99 are yieldingly extensible relative to thebody of the brushes so as to maintain contact with the trolley wireswhen the carrier is slightly raised, as will be hereinafter described.The trolley wires may be connected to a suitable source of electromotiveforce by leads indicated at it? (Fig. 7).

As shown, the bus-bar 1 at the left hand side of the tank, as viewed inFigs. 1 and 6, is provided with raised portions in the form of platesI09, preferably of copper, of progressively increasing thickness fromone end of the tank to the other, as illustrated in Figs. 8 and 9, theseplates being secured to the bus-bar in any convenient way as, forexample, by screws l i I (Figs. 11 and 12) or by welding or brazing, sothat the plates will be in electrical communication with the bus-bar. Asshown, the carrier is provided with a cross-bar H3 having a dependingportion H adapted to rest upon these plates. This cross-bar is integralwith the carrier side bars 65, and as the cross-bars 69 are alsointegral with those side bars, and the shafts 15 are in electricalcommunication with the metal sleeves I3 supported by'the cross-bars 59,the vessels A are electrically connected to the bus-bar I when thecross-bar H3 rests upon any of the plates Hi9.

For supporting the carriers at the side of the tank opposite the platesI89 is provided a horizontal rail l i 5 coextensive with the length ofthe tank. This rail, as shown, is carried by spaced brackets Ill, and onthe rail are plates N9 of insulating material, which plates arepositioned directly opposite the plates Hi9 and are of the samethickness as the latter. The carrier crossbar 6? adjacent the rail H5has a depending portion i2I similar to the depending portion N4 of thecross-bar H3 at the opposite side of the tank, which depending portionl2i is adapted to rest upon these plates H9.-

Supported by each of the brackets II"! at opposite sides of the tank isarail I23 coextensive with the length of the tank. At each end thecarrier is provided with a pair of wheels 25 1 adapted to ride on theserails when the carrier is moved off t-e plates i533 and H9, these plateslifting the wheels of)? the rails when the carrier is moved to positionit on the plates. As a result the wheels ride on the rails only when thecarrier is being moved lengthwise of the tank from one pair of theseplates to the adjacent pair. As will be clear from Fig. 8, the rails I23are upwardly inclined from one end of the tank to the other so that theplates at each station. will raise the wheels of the carrierapproximately the same distance from said rails. As shown, the bodyportion i2? (Fig. 6) of the wheels 525 is formed of insulating materialso that the rails 523 are insulated from the carrier.

It will be understood that by the above construction the plates Hi9 andM9 being of progressively increasing thickness cause the depth ofimmersion of the vessels A to be progressively decreased as they areprogressively placed over difierent anodes by moving the carrierlengthwise of the tank to place them on different plates. The hei hts ofthe upper surfaces of the plates may be readily varied by machining offthose surfaces or by building them up or substituting difierent plates,so as to compensate for settling or warping of the tank and forcontrolling the depth of immersion of the vesselswhile over therespective anodes.

For moving the carriers lengthwise of the tank the cross-bars 57 atopposite of the carrier are shown as provided with projecting bar-likemembers I29 formed of insulating material. Extending lengthwise oi therails is shown a chain I the upper run of which is positioned beneaththese members. This chain is of usual construction except that pairs ofopposite side links I33 at spaced points along the chain have upwardlyprojecting portions 35 (Figs. 1, l, 5, and 14) which are adapted toengage with the members lZQ of the carriers when the chain i moved. Bymoving the chain intermittently it in this way is efiective to push thecarriers to position the vessels carried thereby successively overconsecutive anodes. As illustrated, the chain passes around sprocketwheels it! carried by the brackets ii? at opposite ends or" the tank.The portion of the upper run of the chain between these sprocket wheelsis supported by flanged wheels 35 carried by the intermediate bracketsIiI, while the lower run. of the chain is supported by sprocket wheelsMi (Fig. 14%) also carried by the intermediate brackets i ll. Asillustrated in Figs. 14 and 15, the sprocket wheels MI are so designedthat they may enter the spaces between the projections I35 at oppositesides of the chain so as to engage with the body of the latter.

As shown, the chains I3I at opposite sides of the tank are each drivenby a chain Hi3 (Fig. '7) having a sprocket wheel connection with acommon shaft I45, so that the chains I3I will be driven in unison. Fordriving the shaft I 45 is provided an electric motor I41 adapted to beconnected in driving relation to the shaft through anelectro-magnetically controlled clutch, the clutch elements of whichlatter are schematically indicated at I49 and the energizing winding atI5I. The clutch as shown is indicated in open position so that thechains ISI will be stationary while the articles are over the anodes.Conveniently the motor is connected to the clutch through a reductiongearing, the casing of which is indicated at I53. For intermittentlyenergizing and deenergizing the winding IEI of the clutch, so asintermittently to open and close the latter, is provided a synchronousmotor sche matically indicated at i555, which motor slowly turns a diskI51 of insulating material connected to the motor through a reductiongearing the casing of which is indicated at I59. As shown, the disk isprovided at its periphery with a segment SI of conductive materialadapted intermittently to contact with a brush I63 connected to oneterminal of the clutch energizing winding I5I, the other terminal ofwhich winding is connected to one side I65 of a line for energizing thiswinding. The other side I51 of this line is connected to a brush H59contacting with a ring I II of conductive material carried by the diskI51, which ring is connected by a lead I73 to the conductive segment IEIon the disk. As a result, when the disk is slowly rotated to cause thebrush I63 to contact with the segment It! the winding I5I of the clutchwill be energized to cause the clutch to close, and, while it is closed,the motor I4! will move the chain to cause the carriers to betransferred from over one set of anodes to the immediately adjacent set.The angular length of the segment is so designed with relation to thespeed of the disk I51 that the chain will stop moving as soon as thecarriers are placed above each set of anodes.

For supplying the plating current is shown a generator I75 the oppositeterminals of which are connected by l ads IT! to the opposite busbars 1,respectively. These bus-bars preferably are not continuous, but areformed in sections connected to the generator terminals in parallel sothat the amount of current carried by each section will be reduced. Asindicated in Fig. 7, the adjacent ends of these sections are separatedby insulating blocks H9. As schematically shown inFig. '7, the fieldwinding of the generator is provided with a voltage control section I8Icontrolled by a switch 683 adapted to be operated by a solenoid Iconnected in series relation with the winding Hit of theelectro-magnetic clutch, so that when this latter winding is energizedthe solenoid will be simultaneously energized to cause the switch M3 toclose and thus reduce the voltage of the generator to a low value. Thisprovides that when the clutch is closed to cause the carriers to bemoved the plating current is substantially interrupted and will not beagain established until the chain ceases to move, so that arcing willnot occur.

As pointed out in applicants patent above referred to, it is ofimportance, in plating the lower portion of a cooking vessel with arelatively thick layer of copper or. other metal for distributing theheat applied to the vessel, to have the marginal portions of the platinggradually taper to a feather cedge merging into thesurface ofthe basemetal. Although-excellent results in these respects may be secured byuse of the shield above mentioned, it has been found that improvedresults can be secured bygradually decreasing the immersion of thevessel as the plating operation is continued. Fol-example, if the vesselA (Fig. 22) is initially immersed for a depth of about by graduallydecreasing the depth of immersion to about the tapered portion I81 ofthe plated layer I89 may be much more readily secured and'its shapereadily controlled. Various shapes of vessels may .be readily plated inthis way as, for example, the approximately square cornered vessel AAshown in Fig. 23, with which shape of vessel the opening in the annularshield 6I is-preferably so designed as to cause the plating layer [9| tobulge considerably adjacent the corners of the vessel, as indicated atI93, so as to protect the plating from injury at the corners ofthevessel during handling of the latter when subjected to use in thekitchen.

It has been found, for example, that in cladding a cooking vessel .ofthe shape shown by Fig. 22 or 23 and of material ,such as stainlesssteel, aluminum, or iron requiring, or improved by, .a copper claddingfor distributing the heat, satisfactory results commonlywill be securedwith a cladding about 0.03" thick on the bottom of the vessel, and thata satisfactory tapered layer can be secured by causing the cladding tobe plated in eighteen steps, each electrodepositing on the bottom of thevessel a layer about 0.0017 thick. With a current density of about350amperes per square foot of cathode surface and a sulphuric acidelectrolyte consisting of about by weight of sulphuric acid and byweight of copper sulphate such a layer may be deposited in about 5minutes. In this operation the vessels may be rotated at such linearspeed at the major diameter of theimmersed portions as corresponds toabout 250 R. .P. M. for a vessel 7 inches in diameter. At this speed athin film of electrolyte is drawn up the walls of the vessel for aboutabove the normal electrolyte level, and due to the attenuation of thisfilm the deposition of copper from it proceeds at a very slow rate ascompared to the rate of deposition on the bottom of the vessel. Thisresults in the metal deposited from the film-merging into the surface onwhich it is deposited. It will be understood that by progressivelydecreasing the immersion of the article the marginal portion of thelayer deposited on the vessel when it is over each anode will overlapwith the marginal portion of the layer deposited when it is over thepreceding anode. For example, if the depth of immersion is decreased%"'in eighteen equal steps as above described, each layer will overlapthe other about 0.02. So as to have the rate of deposition at eachstation approximately the same, the anodes preferably are positionedprogressively at a higher elevation as the row of anodes progresseslengthwise of the tank, so as to have them in approximately the samerelation to the bottom of the vessel as the depth of immersion of thelatter is progressively decreased. In cladding the vessel according toFig. 22, satisfactory results will be secured with the current density,electrolyte concentration, and speed of rotation of the vesseL-abovementioned,

when the upper level of the :copper shot in the anodes is spaced aboutZinches from the bottom of the vessel and the shield is spaced about 1inch from the bottom of the vessel, the shield having anopeningapproximately 1 to 2 inches less than the diameter of the vessel,and with about 5 gallons of :electrolyte per minute discharged througheach nozzle, the radial openings 39 of the nozzle being about 1% inchesbelow the bottom of the vessel.

In operation the carriers may be placed above the anodes at the firststation in the tank, and may be removed from the anodes at the laststation, by suitable conveyer means of a known type, these conveyermeans preferably liftin the carrier by engagement with the projectingmembers I29 at each end thereof.

It will be understood that preliminary to the plating operation abovedescribed the vessel may be subjected to such treatment as is necessaryto prepare it for such plating. For example, if the vessel is astainless steel cooking vessel, it may be subjected to the preliminarytreatment described in applicants above mentioned patent, namely,roughening the surface to be plated by an anodic treatment 01'otherwise, treating the roughened surface with electrolytically releasedhydrogen by making said surface a cathode in a non-metal bearingsulphuric acid electrolyte, and applying a flash coating to thecathodically treated surface. These operations consume but a relativelyshort period of time, with the result that vessels will be ready to beplaced in the plating tank above described about every 6 minutes. Thevessels may be loaded on the carrier before subjecting them to thesepreliminary treatments, and the carriers moved from tank to tank wheresuch treatments are performed, and upon completion of these treatmentsmay be moved immediately by the above mentioned conveyer to the firststation of the plating tank above described. Therefore, by having anumber of stations in the plating tank, in which the vessels remain arelatively longtime, a continuous operation may be readily performed.For example, a loaded carrier may be started about every 6 minutesthrough the apparatus for performing the preliminary treatment of thevessels, and substantially immediately upon the completion of theoperation of depositing the flash coating, that is to say about every'6minutes, a loaded carrier may be placed at the first station in theplating tank, and then every 6 minutes the carrier may be moved to thenext successive station in the plating tank, the carrier remaining ateach station about 5 /2 minutes. In this way a row of carriers will bemaintained in the plating tank, the end carrier of the row being removedfrom the tank in this example every 6 minutes.

In the form of apparatus shown by Figs. 19 to 21, the wheels I25 of thecarriers remain continuously on the rails I23, the raised plates I63 andH9 being omitted. In this modification the cross-bar II3 carries a brushi515 continuously in contact with the adjacent bus-bar I. As shown, thisbrush has rigidly secured thereto bolts I91 secured at their lower endsinto the brush and slidably extending through openings I99 in thecross-bar, which openings they fit with sufficient tightness to placethem in electrical communication'with the'cross-bar so as to conductcurrent from the bus-bar to the carrier. As shown, the brushes aremaintained in contact with the bus-bar by springs 20I received inopenings 203 in the cross-bar and hearing at their lower ends againstthe brushes. As shown, the rails I23 are upwardly inclined. from one endof the tank I to the other, so that the carrier as it is moved from oneanode station to the other is progressively raised for decreasing thedepth of immersion of the vessels.

In the modification shown by Figs. 16 to 18 the cross-bar H3 of thecarrier permanently contacts with the adjacent bus-bar I, while theinsulating plate 95 which, as shown in Fig. 1, supports the motor 93 andbrushes 91, is provided with a downwardly projecting portion 205 whichrests upon the adjacent bus-bar I, so that the carrier is supported onthese two bus-bars. For raising the carrier as it travels along thetank, so as to vary the depth of immersion, the two bus-bars I, as shownin Fig. 18, are upwardly inclined from one end of the tank to the other,being for this purpose supported on an insulating strip 291, which stripis like the insulating strip 5 of Fig. 1 except that it is ofprogressively increasing thickness as it extends from one end of thetank to the other.

In this last mentioned modification each of the projecting members I29at the opposite ends of the carrier is provided, on the side thereofengaged by the spaced pairs of projections I35 of the chain, with ablock 209 adapted to be embraced by the adjacent pairs of projectionswhen the latter engage with said member. This construction causes theprojections on the chains to hold the carriers against substantialendwise movement on the bus-bars I. For facilitating entry of the blocks299 into the spaces between the chain projections I35 when the carriersare initially placed over the tank, the upper ends of said projectionsare shown at 2H as bent outwardly to dorm a. flared opening betweenthem.

It will be understood that within the scope of the appended claims widedeviations may be made from the forms of the invention herein describedwithout departing from the spirit of the invention.

We claim:

1. In an apparatus for electrodepositing on bottom and side wallportions of the outer surface of revolution of a metal cooking vessel, ametallic coating which on said side wall portions is of graduallydecreasing thickness as it approaches its upper edge portion and mergesat its upper edge portion into said surface, which apparatus comprises atank adapted to contain electrolyte at a predetermined level, adepending rotatable chuck for supporting the vessel, a travelingsupporting carrier for the chuck, guide and supporting means for saidtraveling carrier, said guide and supporting means including:progressively elevated portions formed at spaced intervals, automaticmeans for intermittently moving said carrier to said progressivelyelevated portions to position said chuck at predetermined levels withrespect to the electrolyte in said tank, power driving means forrotating said chuck mounted on said traveling carrier, and means forsupplying power to said power driving means at said spaced progressivelyelevated portions.

2. The apparatus according to claim 1 in which electrical contactelements are arranged at the spaced elevated portions, the carrierincluding means constituting an electrical contact which when thecarrier is at each oi said elev ated portions forms an electricalcontact with the contact element thereat, and means comprising parts ofconductive material of the chuck in electrical communication with thecontact of the carrier for making the vessel a cathode while at eachelevated portion.

3. The apparatus according to claim 1 in which the spaced elevatedportions for the carrier each includes means constituting an electricalcontact, the contact at each spaced portion being at a higher level thanthe contact at the preceding spaced portion, the carrier being ofconductive material whereby when it rests on the contact of a spaced|portion it is \placed in electrical communication therewith, the chuckhaving a shaft of conductive material rotatably supported on the carrierand in electrical communication therewith, and the chuck being ofconductive material in electrical communication with said shaft, wherebywhen the carrier is supported upon said spaced portions the vessel isplaced in electrical communication with the contacts of said portionsfor making it a cathode.

4. In an apparatus for electrodepositing on the bottom and side wallportions of the outer surface of revolution of a metal cooking vessel, ametallic coating which on said side wall portions is of graduallydecreasing thickness as it approaches its upper edge portion and mergesat its upper edge portion into said surface, which apparatus comprises atank adapted to contain electrolyte at a predetermined level, adepending rotatable chuck for supporting the vessel, a travelingsupporting carrier for the chuck, a series of anodes in said tank inspaced relation to each other, supporting means for said travelingsupporting carrier adj acent each of the sev eral anodes of said series,said supporting means being at progressively greater predeterminedelevations in the direction of travel of said travel ing supportingcarrier, power driven means for automatically intermittently moving saidtraveling supporting carrier successively onto said progressivelyelevated supporting means for positioning said chuck successively abovethe several anodes of said series at \progressively increasingpredetermined elevations with respect to such electrolyte, power drivingmeans mounted on said supporting carrier for rotating said chuck. andmeans for supplying power to said power driving means when saidtraveling supporting carrier is supported by said supporting means.

JAMES M. KENNEDY. ARTHUR P. KNIGHT. HAROLD J. LEE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 75,258 Forbes Mar. 10, 1868234,775 Herskell Nov. 23, 1380 1,298,155 Anthony Mar. 25, 1919 1,453,419Thompson May 1, 1923 2,044,431 Harrison June 16, 1936 2,098,813 RosseauNov. 9, 1937 2,138,938 Plenrsler Dec. 6, 1938 2,363,973 Kennedy et alNov. 28, 1944 FOREIGN PATENTS Number Country Date 4,120 Great Britain of1897 17,717 Great Britain of 1907

1. IN AN APPARATUS FOR ELECTRODEPOSITING ON THE BOTTOM AND SIDE WALLPORTIONS OF THE OUTER SURFACE OF REVOLUTION OF A METAL COOKING VESSEL, AMETALLIC COATING WHICH ON SAID SIDE WALL PORTIONS IS OF GRADUALLYDECREASING THICKNESS AS IT APPROACHES ITS UPPER EDGE PORTION AND MERGESAT ITS UPPER EDGE PORTION INTO SAID SURFACE, WHICH APPARATUS COMPRISES ATANK ADAPTED TO CONTAIN ELECTROLYTE AT A PREDETERMINED LEVEL, ADEPENDING ROTATABLE CHUCK FOR SUPPORTING THE VESSEL, A TRAVELINGSUPPORTING CARRIER FOR THE CHUCK, GUIDE AND SUPPORTING MEANS FOR SAIDTRAVELING CARRIER, SAID GUIDE AND SUPPORTING MEANS INCLUDINGPROGRESSIVELY ELEVATED PORTIONS FORMED AT SPACED INTERVALS, AUTOMATICMEANS FOR INTERMITTENTLY MOVING SAID CARRIER TO SAID PROGRESSIVELYELEVATED